Ship-propeller.



G. A. SCHLOTTER.

SHIP PROPELLER. APPLICATION FILED DEC. 9, 1907. v

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Whig J Patented May 18, 1909.

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GEORG ARTHUR SCHLOTTER, or. DRESDEN, GERMANY. w w V snrr-rnornmnn.

. Application filed. December 9, 1907. Serial No. 405,738.

To all whom t'tmay concern: 'Be it known that I, Gnone ARTHUR. SCHLOTTER, a citizen of the German Empire, residing at Dresden, A., Kingdom of Saxony, Germany, have invented new and useful Improvements in Ship-Propellers, of which the following is a description.

My invention relates to propellers for working in elastic or inelastic fluids, and con- 'sists in the special construction of blades, as-

hereafter set forth, and illustrated in the acc'ompanying drawings, in which Figure 1 shows an elevation in a plane at right angles to the axis; Fig. 2 is a diagrammatic illustration of the outline of the blade and the manner in which its form is determined; Fig. 3 is a diagrammatic view of similar character-in a plane parallel with the axis.

In these drawings, 1 is a circle assumed as the circumference of the propeller wheel, and the line a-b the radius. The direction of rotation (to the right) is indicated by the arrow. An angle 3 is assumed as the required inclination of the blades. This angle is located at the circumference and in rear of the radius, and is included in this radius and I a-line 4 extending from the point 6 on the circumference 1. I

From the center of the radius 2 a half circle 5 is struck, and the point of intersec' tion of line 4 and semicircle 5 is indicated at 6. The lineb-fi determines the generatrix of the blade and its position. Concentric With circle 1 an inner circle 13 is struck tangential to line 4, and determining approximately the inner working extremityof the blade, the boss 14 being farther within, and the root of the blade extended to the boss through this space. It will be understood that we are dealing now with the pressure or working side of the blade, and the generatrix which determines this surface oxtends from the circumference of the screw,

' which is the outer extremity of the blade, to

Specification of Letters Patent.

Patented May 18, 1909.

circle 13 from oint 6 to point 12, and thus produces what call thehelicoidal surface of the blade.

I have assumed, in the last preceding ara-. graph, the extreme points 8 and 12,. .lhese points determine the breadth of the blade. To establish these points, I erect upon the line.a'b from the point 6 of intersection of lines 4 and 5, a perpendicular 7, the per en inner imaginary cylinder. corresponding-..to

dicu'lar striking the line at h. The line -h I (cosine of angle 3), determines the breadth of the blade'at the outer edge, that is to say, the rear point 8 is laid off on the circle 1, at a distance from point I), (the most advanced point. of the blades) a distance e 11:11 to the line b-h. The per endicular 7' etermines the height of the b ade, that is to say, the generatrix 4 is guided spirally around the circle 1 until it reaches the point 8 and 12, an

axial distance equal to the line .7. The generatr'ur, in the last positions 8 and 12, now

determines the rear edge of the blade, and.

with the section of the circle 1 included between lines 4; and 10 (the initial and the terminal positions) bounds the working face of the blade i As heretofore stated, the circle 13 indicates the inner boundary of the working parts of The roots of the blades extend the blades. from this line to the boss 14, to which they arefixed in any convenient way.

In the construction above described, the generatrix was assumed as arranged in a plane which is at right angles to the axis of the propeller. It will be evident that this position referred to in the last preceding paragraph may be varied, and that the generatrix may be in a plane inclinedto that axis, asshown in Fig. 3, where the line 4 indicated the gener'atrix so inclined. Y

It will be obvious that the same description applies to all the blades.

I claim;

' 1. A propeller comprising the helicoidal blades, each of which is formedby the movement of a generatrix placed and moved in a plane at right angles to the axis of the propeller, said blades being all bounded by a circular line which determines the circumference of the propeller, and each blade by the lines 4 and 10, which are tangential to a cylinder concentric with the axis of the propeller, said blades also having roots joining their inner ends to the hubor shaft, all sub-' s'tantially as described.

2. A propeller comprising the helicoidal 1 blades also having roots joining their inner blades, each of which is formed by the moveends to the hub or shaft, all substantially as ment of a generatrix placed and moved in a described.

plane at right angles to the axis of the pro- In testimony whereof I afiix; my slgnatlire 5 pellerl, 9],: thedargle describeld, said blaigeigein the presence of two Witnesses. mg al oun e by a circu ar line W '0 e F v termines the circumference of the pro eller, ARTHUR H Q and each blade substantially by the lmes 4 Witnesses: and 10, which. are tangential to a cylinder OTTO WOLFE,

10 concentric with the axis of the propeller, said O. FRANZ STAMMER. 

